Various analytical instruments have been developed for making optics-based measurements (e.g., fluorescence, luminescence, and absorbance) as part of assays useful in the life science industry. Many analytical instruments are designed to carry out only one or a few dedicated types of measurements. On the other hand, multimode analytical instruments, also referred to as multimode readers, are designed to perform multiple analytical assays in a single instrument. Multimode analytical instruments may be designed to be re-configurable to enable a user to select different types of measurements to be performed. Some multimode analytical instruments utilize application-specific cartridges to enable re-configuration. Examples of multimode analytical instruments are described in U.S. Patent Application Nos. 2005/0012929; 2005/0105080; and 2003/0048447, for example. Additional examples include U.S. Pat. No. 8,119,066, and U.S. Patent Application Pub. No. 2012/0077282.
In the case of performing flash luminescence, a reagent must be injected onto the sample to induce the luminescent response. In the case of multimode readers that utilize cartridges, there is a need for integrating the reagent injection function and the luminescence reading function into a single cartridge. Moreover, because luminescence experiments require a fluidic system to dispense reagent liquid, such a system must be periodically rinsed and primed, and possibly cleaned or decontaminated. Hence, luminescence experiments may entail a variety of different types of liquid flows, which may lead to undesired contamination of optics components of the sample analyzing apparatus and other problems. As examples, contamination may result from electrostatically accelerated droplets, the generation of uncontrolled droplet sizes, the unwanted dispensing or spilling of liquid onto sensitive optics components, and the development of leaks in the fluidic system. Therefore, there is also a need for sample analyzing apparatuses, including those utilizing luminescence cartridges, which address such problems.